Federated Learning Model Poisoning Detection via Activation Clustering

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Solution Overview

Problem

Federated learning systems are vulnerable to model poisoning attacks, where malicious clients send crafted updates that misclassify attacker-chosen samples, and existing techniques fail to effectively defend against these attacks.

Innovation Solution

Implementing a multi-layered defense system that includes statistical analysis of class-specific misclassification rates, neural network activation clustering, and client-driven feedback to detect and block poisoning attempts, allowing for flexible operation of these techniques alone or in combination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If federated learning with secure aggregation is used to protect data privacy, then data confidentiality is improved, but the system becomes vulnerable to model poisoning attacks

Engineering Contradiction:
Improvedata confidentialityVSAvoidresistance to model poisoning attacks
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent applies preliminary action by performing poisoning detection analysis on model updates before they are aggregated into the global model. The server receives model updates from clients, conducts detection analysis to identify poisoned updates, and only aggregates updates that pass the detection. This preventive approach blocks malicious updates before they can compromise the global model, resolving the contradiction between maintaining data confidentiality through secure aggregation and preventing model poisoning attacks.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If model updates are aggregated from all clients to improve model performance, then learning effectiveness is improved, but malicious updates can poison the global model

Engineering Contradiction:
Improvemodel training effectivenessVSAvoidmodel poisoning impact
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies the taking out principle by extracting and removing poisoned model updates from the aggregation process. The detection analysis identifies malicious updates by analyzing characteristics such as activation clustering patterns and loss function behavior, then excludes these updated from being aggregated into the global model. This allows the system to maintain high learning effectiveness by aggregating legitimate updates while filtering out harmful ones, resolving the contradiction between utilizing all client contributions and preventing poisoning.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If detection analysis is performed on all model updates to ensure security, then security is improved, but computational overhead and processing time increase

Engineering Contradiction:
Improvesecurity against poisoningVSAvoiddetection processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies partial action by performing detection analysis selectively rather than uniformly on all model updates. The system uses efficient detection mechanisms that analyze specific characteristics of updates (such as activation patterns and loss behavior) to identify poisoned updates without conducting exhaustive analysis on every single update. This approach maintains high security by detecting poisoned updates while minimizing computational overhead and processing time, resolving the contradiction between thorough security checking and efficient processing.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11616804B2Thwarting model poisoning in federated learning
Publication Date: 2023.03.28 NEC CORP
  • US11616804B2 patent drawing
  • US11616804B2 patent drawing
  • US11616804B2 patent drawing

AI summary

A method detects model-poisoning attempts in a federated learning system. The federated learning system includes a server orchestrating with clients to train a machine-learning model. The method includes receiving, by the server, results of a poisoning detection analysis. The poisoning detection analysis includes at least one of an analysis of class-specific misclassification rates or an analysis of activation clustering of a current state of the machine-learning model.